Question: $ { \left[\begin{array}{rr}{2} & {1} \\ {4} & {2} \\ {-2} & {3}\end{array}\right]-\left[\begin{array}{rr}{1} & {4} \\ {-1} & {-2} \\ {-1} & {4}\end{array}\right] = {?} } $
Explanation: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}-{1} & {1}-{4} \\ {4}-{-1} & {2}-{-2} \\ {-2}-{-1} & {3}-{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{1} & {-3} \\ {5} & {4} \\ {-1} & {-1}\end{array}\right]}$